This is an interview of Mike Arsenault, product manager at GrassHopper group, which built an application called Spreadable, which was eventually shut down.
Q: Did you talk to customers or just start building?
We just started building. This was probably the single biggest mistake we made. We made the assumption that since our program worked so well for Grasshopper, we could just port over the same functionality to Spreadable. There were major problems with that logic. First, very few of the customers who came to us had businesses like ours. We learned later that there is actually a threshold in terms of customer count for a Spreadable powered referral program to be successful.
For the experienced entrepreneur, the mistakes listed by Mike seem painfully familiar, and even obvious.
If you're on your first startup and thinking "our startup is different, that won't happen to us, even though we're doing the same things", don't. Not getting customer feedback early enough is the classic startup-killer mistake.